The American set was pretty much the same as ours wasn't it?
Think I read somewhere that the American version was going for a complete different look this year after Cowell said he thought it looked too dark and serious last year. Not sure if that will extend over the Atlantic. All the American publicity shots so far have featured a lot of bright green and pink. Ours imply a tweak, but nothing radical.
It isn't really the set that's the problem with making the American one serious, it's the overall production values and the way they actually use the set. Whenever I watched it was often lit blue so it was dark, but its more or less the same as the British one yet the British one was usually lit red, yellow or orange and they used the lighting much more on performances, particularly upbeat ones or ones with joke acts. Also, the British show is much more tongue in cheek in the way it's produced, whereas the USA one came over a bit pretentious- just like how The Voice UK fell down in its final stages.